SEOUL, Oct. 19 (Yonhap) -- South Korea has signed a nuclear energy cooperation agreement with Hungary, the foreign ministry said Saturday, a deal expected to help Seoul export nuclear power plants to the European nation.

Foreign Minister Yun Byung-se signed the accord with his Hungarian counterpart Janos Martonyi in a ceremony in Seoul on Friday, the ministry said. Hungary is the 28th country to sign such an agreement with South Korea.

The agreement is scheduled to take effect 30 days after the sides exchange documents notifying each other that their domestic procedures for the deal are completed. The signing came two months after the two countries reached full agreement on a final draft in August.

The agreement, which is valid for 40 years, calls for cooperation in research and development, designing, construction and operation of nuclear reactors for peaceful purposes.

Hungary has four power-generating nuclear reactors in operation and is planning to build more, with a bidding process expected to begin later this year, Seoul officials said.